How Many Black Neon Tetra in a 20-Gallon Tank?
In a 20-gallon tank you can comfortably keep about 6–25 Black Neon Tetra. As a schooling species, never keep fewer than 6.
Why
Stocking is driven by adult size and waste output, not just fish count. Black Neon Tetra reaches about 1.6" with a light bioload, and needs 73–81°F water at pH 5.5–7.5. Always cycle the tank and test water before adding livestock.
| Adult size | 1.6" |
|---|---|
| Minimum tank | 15 gallons |
| Temperature | 73–81°F |
| pH | 5.5–7.5 |
| Temperament | Peaceful |
| Schooling | Yes — group of 6+ |
| Diet | Omnivore |
| Care level | Easy |
| Origin | Paraguay basin, Brazil |
More fish for a 20-gallon tank → Black Neon Tetra tankmates →